Public Finance

Public finance is a field of economics concerned with paying for collective or governmental activities, and with the administration and design of those activities. The field is often divided into questions of what the government or collective organizations should do or are doing, and questions of how to pay for those activities. The broader term (public economics) and the narrower term (government finance) are also often used.
The proper role of government provides a starting point for the analysis of public finance. In theory, private markets will allocate goods and services among individuals efficiently (in the sense that no waste occurs and that individual tastes are matching with the economy's productive abilities). If private markets were able to provide efficient outcomes and if the distribution of income were socially acceptable, then there would be little or no scope for government. In many cases, however, conditions for private market efficiency are violated. For example, if many people can enjoy the same good at the same time (non-rival, non-excludable consumption), then private markets may supply too little of that good. National defense is one example of non-rival consumption, or of a public good.